Thermally sensitive valves



F. A. SIMPSON THERMALLY SENSITIVE VALVES Jan. 23, 1962 3 Sheets-Sheet 1 Filed NOV. 9, 1959 R m M v w Jan. 23, 1962 F. A. SIMPSON 3,018,054

THERMALLY SENSITIVE VALVES I Filed Nov. 9, 1959 3 Sheets-Sheet 2 lA/l/E N TOR FR 505R ICK fl, SIM/"301V ATTORNE);

Jap. 23, 1962 F. A. SIMPSON 3,

THERMALLY SENSITIVE VALVES Filed Nov. 9, 1959 3 Sheets-Sheet 3 I I 20 I I I IE 6 g 1 32 I 35 o I I I l I I-3O //VVEN7 OR FREDERICK A ammo ZWMJMTM A TTORN'E X 3,615,954 THEEMALLZ L EIJEQETIVE VALVES Frederick Arnold Simpson, loynings, Penn Road, Eeaconsfield, England Filed Nov. 9, 1959, Ser. No. 851,622 4 Claims. (Cl. 236-345) The present invention relates to thermally controlled valves of the type having a cylindrical casing in which three ports are provided, at least two of which are angularly spaced around its curved periphery and are controlled by a rotor which has two arcuate port shutter members and is carried on an axially arranged spindle. 'In this type of valve the rotor can be rotated through a limited angle from a position in which one rotor controlled port is obscured by one shutter member and the other is open through positions in which both the rotor controlled ports are partially obscured to a position in which the second port is obscured by the other shutter member and the first port is fully open. The third port is always open and may be formed either in the periphery of the valve casing or in an end cover.

It is a characteristic of this type of valve that the force required to control the flow of fluid through the valve is small in comparison with that required in other forms of valve and in this type of valve a bimetallic coil producing quite small force has been used to control the rotor position.

Bimetallic coils have, however, a tendency to oscillate and, in consequence, are not capable of maintaining the temperature of the fluid passing through the valve within a narrow temperature range.

Valves of the present type are employed, for example, for the control of the temperature of the coolant of an engine, one of the two rotor-controlled ports being connected to a radiator inlet whilst the other is connected to a by-pass leading back to the engine, so that with rise and fall of the temperature of the coolant entering the valve from the engine, a greater or less proportion of coolant is passed through the radiator.

It is an object of this invention to provide a valve of the present type in which the rotor is held in an angular position determined by the temperature of the incoming fluid and cannot oscillate about such position to any appreciable extent.

It is already known to actuate poppet and like valves in which a valve member moves linearly, by means of a temperature sensitive element in which a piston rod is forced outwardly against the resistance of a return spring by the expansion of wax held in an enclosed chamber, on rise of temperatur The wax in such temperature sensitive elements is usually mixed with finely divided metal, such as copper powder, to improve its temperature response. One example of a temperature sensitive element of this type is shown in British Patent No. 576,779.

It is a characteristic of waxes that they have a high co-etficient of expansion close to their melting point and a Wax-filled temperature sensitive element of this type produces a relatively large movement of the piston rod within a stated temperature range.

This type of temperature sensitive element is usually arranged so that the piston rod does not commence to move until a predetermined temperature is reached at the bottom end of the stated temperature range of the element.

In known forms of valve controlled by this form of temperature sensitive element, the element has been utilised to produce a direct thrust to raise or lower a valve member.

Because of the low force required to turn the rotor of a valve of the present type, a temperature sensitive element of this type may be employed to provide a relatively large valve movement, as compared with other types. of valve of the same bore.

in its broadest aspects the present invention provides a thermally controlled valve of the type described having a rotor rotatable about a stationary spindle and controlled by means of a linearly expanding wax-filled thermosensitive element of the type referred to above secured either to the spindle or to the rotor and connected by a pivoted linkage to the rotor or to the spindle eccentrically of the axis, so that the rotor will turn about the axis of the spindle with change of temperature, at least within a predetermined temperature range.

The thermosensitive element is preferably clamped to the spindle of the valve so as to be non-rotatable in relation thereto and is located between a pair of cross webs supporting the shutters of the rotor.

The invention is hereinafter further described with reference to the accompanying drawings, wherein:

FIGURE 1 is a plan view of a complete valve.

FIGURE 2 is a section on line 11-11 of FIGURE 1.

FIGURE 3 is a partly diagrammatic section on line IIIlIl of FIGURE 2.

FIGURE 4 is a similar section of a modified valve.

FIGURE 1 gives an external view of a rotary valve of the type to which the present invention refers. The valve comprises a body with three connection flanges for ports 1, 2 and 3, which are respectively intended to serve as an inlet, an outlet to a radiator and a by-pass outletback to the water iacket of an engine. The inlet port 1 could alternatively be provided in one end cover of the casing. In this figure there are are also shown an end cover 4, which is bolted to the body and emergency lever 5, which can be used to turn the spindle 6 and the rotor 7 bodily to a safe position in the event of the temperature sensitive element becoming jammed when the bypass port is closed wholly or in part, which would be reflected by an excessive rise in coolant temperature in the engine.

Referring now to FIGURES 2 and 3, it will be seen that a temperature sensitive element 8 is secured to the spindle 6 by means of a clamp 9 in which the barrel 10 of the element 8 is held. The piston rod 11 of the element 8 is forced outwardly by the thermal expansion of Wax held in an enclosed chamber 14 which is secured to the barrel 10 and is threaded into a head piece 12. Transverse pivot pins 15 are fitted into the head piece 12 and serve as anchorages for links 16 connected to a sliding collar 17 acted on by a heavy return spring 18, which produces the force necessary to push the piston 11 back into the barrel when the wax contracts on cooling.

The ports 2 and 3 are controlled (see FIGURE 3) by the arcuate shutter members 19 and 20, which are connected by cross webs 21 to form the rotor 7. The head piece 12 is connected to the cross webs 21 by links 22 pivoted on the pivot pins 15 and on pivot pins 23 threaded into the cross webs 21.

The operation of the valve is very simple. It will be apparent that increase in the temperature of the liquid to which the wax chamber 14 is subjected willllead. to the piston rod 11 being extended against the force of the return spring and this will gradually swing the rotor 7 from the position shown in FIGURE 3 to a position in which the port 3 is closed by the shutter 20 and the shutter 19 uncovers the port 2.

It the element 8 fails when the valve rotor 7 is in the position shown in FIGURE 3, the valve can be put into a safe condition by turning the spindle 6 in the direction indicated by the arrow by means of the lever '5, thus opening the port 2 and closing the port 3. It will be appreciated that the valve must be constructed so that the spindle 6 has some resistance against rotation so that the spindle '6 cannot be turned by the reaction of the temperature sensitive element 3.

A modified construction is shown in FIGURE 4, in which the rotor turns in the opposite direction on temperature rise to that of the construction described above. Like parts are identified in FIGURE 4 by like reference numerals. This construction is intended to give a greater angular movement to the rotor shutters 19 and 2%, which is necessitated where the inlet ports occupy a wider angle in the periphery of the valve body. To achieve this result the movement of the piston rod of the element is magnified by transmitting it through a lever system.

The piston rod is threaded into a modified head piece 39, which is pivoted at 353 to a pair of parallel links 31. The links 31 are pivoted to a swinging fulcrum, formed by a pivot pin 32, held in a link 33 pivoted at 33 to the clamp member 9. The other ends of the links 31 are pivotally connected at 31 to a push rod 34, which is a sliding fit in a rotatable member 35 connecting the transverse webs 23 on a pivot axis 35'.

It will be observed that the head piece 34} is connected much closer to the fulcrum 32 than is the push rod 34, so that the movement of the push rod is magnified in comparison with the movement of the piston rod.

In this construction the limits of the movement of the shutter members 19 and 29 are determined by stops as and 37. The thrust from the rod 34 is therefore transmitted to the member 35 through a spring 38 so as to avoid damage in the event of excess expansion of the element 8.

As in the earlier example the port 2 can be opened in emergency by turning the spindle 6 in the direction indicated by the arrow.

Both the constructions described above are capable of a number of variations.

A series of holes at different radial distances are preferably provided in the transverse webs 21 for the insertion of the pivot pins 23 to permit the rotor 7 to be turned through different angles within the range of expansion of the thermosensitive element 8 within its stated temperature range.

The provision of different positions for the pivot pins 23 on the rotor permits the valve to be set so as to operate through different temperature ranges. This adjustment can only be eifected by removal of an end cover plate of the cylindrical valve casing.

I claim:

1. A valve comprising a cylindrical enclosed casing, said casing having three ports therein, at least two of which are angularly spaced around its curved periphery, a stationary spindle extending axially between opposed ends of said casing, a port-controlling rotor rotatably mounted on said spindle, said rotor having two arcuate port-controlling shutter members and at least two cross webs holding said arcuate shutter members in spaced relation, a linearly expanding wax-filled thermosensitive element having a piston rod forced outwardly by thermal expansion of wax held in an enclosed chamber and a return springopposing the piston rod, said element being secured to said spindle at a position between the pair of cross webs on said rotor, a movable head piece on said thermosensitive element, pivot means supported on said head piece, and connecting means pivotally coupled between said head piece and to said webs for transmission of motion from said piston rod to said rotor.

.2. A valve comprising a cylindrical enclosed casing, said casing having three ports therein, at least two of which are at angularly spaced positions in the curved 'side wall of the casing, a stationary spindle extending axially between opposed ends of said casing, a port-controlling rotor rotatably mounted on said spindle for controlling the efiective opening of said two angularly spaced ports in the side wall of said casing, said rotor having thereon two arcuate diametrically opposed shutter members and a pair of cross Webs holding said shutter members in spaced relation, which webs are apertured for receiving said stationary axial spindle therethrough, a linearly expanding wax-filled thermosensitive element having a piston rod forced outwardly by thermal expansion of Wax held in an enclosed chamber and a return spring opposing said piston rod, said element being secured to said stationary axial spindle near a midposition between said opposed ends of said casing, and at least one link connecting the piston rod of said thermosensitive element to one of said cross webs, said connecting link being pivotally connected both to said piston rod and to said cross web.

3. A valve comprising a cylindrical enclosed casing, said casing having three ports therein, at least two of which are at angularly spaced positions in the curved side wall of the casing, a stationary spindle arranged axially between opposed ends of said casing and extending through at least one end thereof, a port-controlling rotor rotatably mounted on said spindle, said rotor having two arcuate port-controlling shutter members and a pair of cross webs holding said arcuate shutter members in spaced relation, said two ports and said shutter members being positioned relative to each other so that only one of said two ports may be fuily closed at any instant, a linearly expanding Wax-filled thermosensitive element having a piston rod which is forced outwardly by thermal expansion of wax held in an enclosed chamber and a return spring opposing said piston rod, said element being secured to said spindle at a position between said pair of said cross webs, coupling means pivotally coupled both to the piston rod of said thermosensitive element and to one of said cross Webs for transmission of motion from said piston rod to said rotor, and manual means secured to the end of said spindle externally of said casing for rotating said axial spindle, whereby adjustment of the position of said rotor shutters in relation to said two ports at a selected temperature may be effected.

4. A valve comprising a cylindrical enclosed casing, said casing having three ports therein, at least two of which are at angularly spaced positions in the curved side Wall of the casing, a stationary spindle extending axially between opposed ends of said casing, a port-controlling rotor mounted on said spindle for controlling the efiective opening of said two angularly spaced ports in the side wall of said casing, said rotor having two arcuate diametrically opposed shutter members and a pair of cross webs holding said shutter members in spaced relation, which webs are apertured for receiving said stationary axial spindle therethrough, a linearly expanding wax-filled thermosensitive element having a piston rod forced outwardly by thermal expansion of wax held in an enclosed chamber and a return spring opposing said piston rod, said element being secured to said stationary axial spindle near a midposition between said opposed ends of said casing, a link pivotally connected to a cross web of said rotor, a lever member pivotally connected to I said pivoted link at one end and pivotally connected to the piston of said thermosensitive element at its other end and a swinging fulcrum member pivotally mounted on said spindle to which said lever member is pivoted.

References Cited in the file of this patent UNITED STATES PATENTS 2,473,097 Hamill June 14, 1949 2,701,102 Albrecht Feb. 1, 1955 2,792,179 Vernet May 14, 1957 2,894,689 Spicer et al July 14, 1959 

